Method for shearing spent nuclear fuel bundles

ABSTRACT

Apparatus and process for shearing long units, such as nuclear fuel bundles, into pieces of predetermined length for further processing. The apparatus comprises a sealable magazine for receiving the bundles, means for urging the bundle forward, a vertical and horizontal gag, or alternately two parallel-acting horizontal gags operated in conjunction with a vertical restraint, for compressing the front portion of the bundle, and a shear blade adjacent to the gags, whereby the nuclear fuel bundle may be urged forward in increments, compressed and sheared into pieces.

United States Patent [191 Ehrman et al.

[ Oct. 9, 1973 METHOD FOR SHEARING SPENT NUCLEAR FUEL BUNDLES [75]Inventors: Chester S. Ehrman, Basking Ridge;

Louis Scheib, Morristown, both of N.J.; Charles S. Worsley, Burlingame;Frank J. Jones, San gruno; Robert M. Freeborg,

Lafayette, all of Calif.

[73] Assignee: Allied Chemical Corporation, New

York, N.Y.

[22] Filed: Dec. 15, 1970 21 Appl. No.: 98,249

[52] US. Cl. 100/39, 83/19, 83/622, 100/42, 100/70, 100/95, 100/215,100/232,

[51] Int. Cl .l B3011 13/00 [58] Field of Search 83/14, 19, 622, 92 SR;100/39, 42, 215, 232, 95, 98, 70, 269 R, 295;

[56] References Cited UNITED STATES PATENTS 2,887,373 5/1959 Winkler eta1. 79/97 R 3,490,999 1/1970 Ravin 204/ 1.5 3,122,038 2/1964 Juras83/622 3,320,051 5/1967 Liberman 100/39 3,283,697 11/1966 Findlay 100/953,005,403 10/1961 Van Endert 100/98 R 3,049,988 8/ 1962 Lindemann et a]100/95 Primary Examiner-Billy J. Wilhite Attorney-Ernest A. Polin [5 7]ABSTRACT Apparatus and process for shearing long units, such as nuclearfuel bundles, into pieces of predetermined length for furtherprocessing. The apparatus comprises a sealable magazine for receivingthe bundles, means for urging the bundle forward, a vertical andhorizontal gag, or alternately two parallel-acting horizontal gagsoperated in conjunction with a vertical restraint, for compressing thefront portion of the bundle, and a shear blade adjacent to the gags,whereby the nuclear fuel bundle may be urged forward in increments,compressed and sheared into pieces.

6 Claims, 12 Drawing Figures PATENTEU 9 I975 SHEEI 10F 7 INVENTORSCHESTER s. EHRMAN LOUIS SCHEIB CHARLES s. WORSLEY FRANK J. JONES ROBERTM. FREEBORG' B W4+ 9m;

ATTORNEY PATENTEDUET w 3.763.770 sum 3 or, 7

INVENTORS VI 6 M E w L m H W E EEW R .E .OF m TSLKR SIRNE UAA HmHRO CCFRQ By QWOYL ATTORNEY PATENTEU 9W5 3.763.770

SHEEI n []F 7 INVENTORS CHESTER S. EHRMAN Q\ LOUIS SCHEIB CHARLES S.WORSLEY FRANK J. JONES ROBERT M. FREEBORG By QMQ'f-Q Ffw ATTORNEYPATENTEDUET 9W 3.763.770

SHEET 5 [IF 7 CHARLES S.WORSLEY FRANK J. JONES ROBERT M. FREEBORGATTORNEY FIGQH PATENTED OCT SHEET 8 OF 7 PATENTEDUBT 9m 3.763.770

SHEET I [If 7 FIG.

METHOD .FOR SHEARING SPENT NUCLEAR FUEL BUNDLES This invention relatesto an improved materialcutting control system and more particularly to amethod for shearing nuclear fuel bundles into units of shorter andpredetermined length. Apparatus to accomplish this operation isgenerally known as a fuel bundle shear. Such an apparatus serves to cutspent nuclear fuel bundles into short sections for feeding to adissolution process wherein the pieces are leached with nitric acid toseparate the acid-soluble uranium values from the insoluble hulls andend fittings.

Fuel bundles are commonly constructed of nuclear fuel-filled tubes up toabout inch in diameter which are banded together by tube sheets intosquare crosssections which may vary up to about 12 inches square. Thesebundles may vary in length up to about 20 feet, and generally have endfittings to hold the assembly together and to serve as distributingheads for cooling water.

The emission of neutrons within a nuclear reactor brings about a degreeof embrittlement in the material of construction of the bundle as wellas in the fuel pellets with which the tubes are filled. Thisembrittlement introduces a problem in the nuclear fuel recovery process,for it can lead to premature breakage of the tubes when the bundle isbeing fed into the shear blade for shearing. This can result inundesirable variations in the length of the cut pieces. It is the aim ofthe present invention to obtain an accurate length of cut. The nuclearfuel must be leached free of the acid insoluble hulls, and the timerequired to obtain complete solution varies with the length of thepieces. lnaccurately cut lengths of tube therefore make process controldifficu'lt and may lead to incomplete removal of the fuel from the tubesections. The ability to control the length of the cut pieces isessential to the proper operation of the shear, and realization of theobjects of this invention.

Shears have been designed in the past for shearing spent nuclear fuelbundles, but these shears are generally limited not only as to thecross-section of the bundles which they will accommodate, but to thelength of the bundles that can be handled as well. In the past it hasgenerally been necessary to remove the end fittings or other hardware bya cutting machine before transferring the fuel bundles to a shear.Although a pressure device is sometimes used to hold and compress thetubes or rods during the shearing operation, the device employed cannotch and distort the individual members, thus causing prematurebreakage of the embrittled tubes and undesirably leading to variationsin the length of the cut pieces.

It is an object of the present invention to provide a practical methodfor cutting fuel bundles of various sizes up to about 12 inches incross-section and up to 20 feet in length without prior disassembly ofthe appara'tus.

It is a further object of this invention to provide a method forshearing off the end fittings of the bundle as a part of the sameoperation in which the entire bundle is cut into lengths of the sizechosen for the subsequent dissolution step.

It is a further object of this invention to provide a method forcompressing the bundles as each length approaches the point of shearing,to facilitate -a clean shear without notching the embrittled fuelelements,

which would contribute to premature breakage of these elements andconsequently to variation in the length of the severed pieces.

It is a further object of this invention to provide for the lateralcharge of the bundles into the shear, for the complete enclosure of thebundle in the apparatus and for the adjustment or insertion of a sidewall to thus align and guide the fuel bundle in its approach to theshearing member.

It is a further object of this invention to provide a method for urgingthe bundle forward through-the apparatus in predetermined increments,for acting upon the end of the bundle with a vertical gag and ahorizontal gag, thus compressing the front portion of the bundle fromtwo directions, or alternately compressing the bundle with twoparallel-acting horizontal gags operating in conjunction with a verticalrestraint, shearing off predetermined lengths of the bundle by means ofa blade, and finally permitting the severed lengths to drop through achute or conduit directly to the dissolution apparatus. (A gag as usedherein is a clamping device which can also effect some collapse of thematerial held.)

lt is a still further object of this invention to provide forunidirectional or two-directional gagging, wherein the gags are arrangedin a removable module or assembly which may be readily removed andreplaced by remote control. The restraining member may optionally beincluded in the removable module together with the gag(s).

These and other objects are accomplished according to our inventionwherein the forward end fitting is cut from a nuclear fuel bundle, theentire fuel bundle is cut into short sections of predetermined lengthand the fit ting and sections are delivered to the dissolution processtogether with the remaining end fitting.

Briefly, the apparatus comprises a chamber, open on one side tolaterally receive the full length of the fuel bundle, means for closingand sealing the lateral opening of the chamber, a movable side wallwhich may be adjusted according to the cross-section of the bundlecontained in the chamber so as to serve as a guide for the fuel bundle,a feed member which urges the bundle forward through the apparatus inpredetermined increments, a vertical gag with limited movement whichfirst subjects the fuel bundle to a compressive force, and then, withits position fixed, serves as a restraint to the bundle while it isfurther acted upon by a horizontal gag, to cooperatively compress thefront portion of the bundle from two directions. Alternately, two ormore horizontal gags and a vertical restraining member are provided,which cooperate to diminish the width of the front portion of the bundlewhile essentially retaining its height. This arrangement can alsoprovide another important service, for if the fuel bundle jams duringthe shearing operation, it may readily be freed by raising the movablerestraining member. A moving shear blade is also provided, preferablyhaving a stepped configuration, to shear the compressed portion of thebundle, and a conduit beneath the shearing member in communication withthe dissolution apparatus through which pieces sheared from the fuelbundle may be conducted to the subsequent dissolution step. In each ofthe two embodiments both gags are preferably contained within aremovable module and their contact faces are contoured to insuresatisfactory compression of the bundle.

More specifically, those portions of the nuclear fuel bundle shear ofour invention which are in direct communication with nuclear material,are contained in a hot cell, and the moving parts are controlledremotely, being actuated by means such as hydraulic and pneumaticcylinders, and electric motors. The chamber which accepts the spentnuclear fuel bundle comprises a magazine which may be opened laterallyfor loading, then closed and essentially sealed. The seal, which is notabsolute, may be achieved, for example, by means of tight fitting lipsor by metal gaskets consisting of multiple layers of resilient metalstrips arranged squeegee fashion along either the moving edges, or thestationary edges to be sealed. When the loading entry of the magazine isclosed, the only other major opening is that through which the bundle isurged when it is to be sheared by the shearing member.

A housing surrounds the shear blade, said housing being in communicationwith the conduit and also with the gag module and magazine, therebyforming a closed, essentially airtight system with the dissolutionapparatus.

Normally, the dissolution apparatus is maintained under slightly reducedpressure to control the flow of fine particles and gases generated byshearing the fuel bundle, and to prevent backflow of acid fumes from thedissolution apparatus up into the shear; hence, air from the surroundinghot cell leaking into the sealed magazine and at other points in theclosed system, flows through the conduit to the dissolution apparatus.

The shearing member comprises a blade having a stepped, a pyramidal oran angular guillotine-like configuration. This slideably arranged shearblade positioned in cooperative relationship with a stationary shearblock is also slideably positioned in sealing relationship with theopening of the magazine through which the fuel bundle extends.Accordingly, the extended blade serves substantially as a relativelygastight gate to the magazine, but permits gas flow through the openingwhen in a retracted position.

The sheared pieces and the end fittings of the fuel bundle drop throughan open ended conduit and are directed thereby to the dissolution stepof the recovery process. Each time the shear blade completes its stroke,it might be expected that it would interrupt the flow of air from themagazine and the surrounding hot cell. Interruption of the flow of airduring the shearing operation would be undesirable; therefore, avalvecontrolled bypass is provided to prevent such an interruption.

During the loading operation, however, the shear blade is fullyextended, thus acting as a gate valve for the opening between themagazine and the housing surrounding the aforesaid open ended conduit.At such times the bypass is also closed to a point where the flow of airis limited to essentially that which would normally be obtained fromleakage into the closed magazine, thereby permitting the loadingoperation without affecting the partial pressure maintained in thedissolution apparatus.

There are many ways in which this air flow can be controlled; forexample, a butterfly valve can be employed, the periphery of the movabledisc of which has an adjustable notch or perforation, or is otherwiseprevented from entirely closing, so that in its position of minimal flowthe opening remaining admits essentially the same flow of air normallyobtained as a result of leakage into the closed magazine.

In operation, such a valve is opened when the magazine is closed and cutoff from the balance of the system by the fully extended shear blade. Itis closed when the magazine is closed, but not cut off from the systemby the shear blade in its retracted position. Most importantly, it isalso closed when the shear blade is fully extended and the magazine isopen for the charging of a bundle, or for any other reason. In otherwords, the valve is controlled so that the flow of air through theconduit to the dissolution apparatus remains essentially constant underall circumstances. Operation of the valve may be based on pressuredifferentials, or it may be operated by mechanical or electrical means.

In the drawings, we have illustrated two embodiments of the invention.

FIG. 1 is a plan view of the preferred embodi-ment, being partially inhorizontal section with covers removed. Minor details have been omitted.

FIG. 2 is a vertical section on the line 22 of FIG. 1.

FIG. 3 is a transverse section on the line 3-3 of FIG. 2.

FIG. 4 is a transverse section on the line 4-4 of FIG. 1.

FIG. 5 is a vertical section showing detail of the removable gag module24 of FIGS. 2 and 3.

FIG. 6 is a vertical section showing detail of the removable gag module24 on line 6-6 of FIG. 5.

FIG. 7 is a cross-sectional view of gags 27 and 30 illustrating theapproximate contour of the holding member or gag block.

FIG. 8 is a plan view of the shearing end of the unit illustrating analternate embodiment wherein two adjacent independently acting gagblocks operate in cooperation with and at essentially right angles to arestraining block, not shown.

FIG. 9 is a half section elevation of the shearing end of the unit online 9-9 of FIG. 8 showing the restraining member.

FIG. 10 is an end view on line 10-10 of FIG. 9, showing deformation ofthe end of the fuel bundle resulting from pressure applied by thehorizontally acting adjacent gags in cooperation with a verticalrestraining member.

FIG. 11 discloses a modification wherein inserts are used to guide thebundle.

FIG. 12 discloses a modification wherein the apparatus side walls arefixed.

Describing in illustration but not in limitation, and referring to thedrawings, FIGS. 1, 2, 3, 8, 9 and 10 show a partially sheared nuclearfuel bundle positioned in the apparatus. In FIG. I a typical nuclearfuel bundle as it comes from the reactor is shown as 17 having fuel endcap 18 and fuel spacers 21. In the illustration the first end cap hasbeen removed by shear blade 25.

In operation, a typical fuel bundle which may vary in cross-section upto about 12 inches or in length up to about 20 feet, is first deliveredto the magazine in a horizontal position.

In preparation for receiving the fuel bundle within the magazine,movable plate 44 of FIGS. 1 and 4 is moved toward side section 46 untilthe distance between these parallel surfaces is just sufficient toaccommodate the particular fuel bundle to be charged, and to insure itsalignment with respect to the shearing mechanism. Alternately, ratherthan a movable wall, appropriately sized or positioned inserts 75 may beplaced along the back wall of the magazine to thus leave just sufficientroom for the selected bundle to be guided in slideable alignment withthe shearing mechanism, as shown, in FIG. 11.

In FIGS. 1, 4 and 8, a movable side 44 is shown powered by driving meansso that it may be moved in a piston-like manner towards or away fromparallel end sec: tion 46 in order to adjust the width of the magazineto the size of the fuel bundle to be received. This movable side 44 isslideably arranged and sealed against the side walls of the magazine atall points along its periphery.

Although this movable side wall 44 ordinarily is adjusted before thebundle is placed in the magazine, it may, if desired, be movedafterward, thus urging the bundle into proper alignment against parallelsurface 46 of FIGS. 1 and 4. Although there are many different ways inwhich movable plate 44 may be moved into position, the method hereillustrated comprises a gear train powered by motor means 47 of FIG. 1which operates outside of concrete barrier 22 enclosing the hot cell.Torque is applied selectively in either direction to rotatable shaft 48which extends through concrete barrier 22, operates through gear box 51,FIG. 1, horizontal rotatable shafting 59 parallel to the magazine, andmiter gears 50 at a plurality of points adjacent to wall 44. At each ofthese points, the center of the driven miter gear is threaded tocooperate with an axially extending screw or worm, one end of which isattached to movable plate 44, whereby the simultaneous unidirectionalturning of all the driven miter gears will urge the screws or worms, andwall 44 attached thereto, toward or away from, end section 46 dependingon the direction of rotation imparted to the driven miter gears by motormeans .47. Wall 44 may also be a stationary member, pre-positioned for aspecific size of fuel bundle, and having no mechanism for lateralmotion, as shown in FIG. 12.

When magazine has been adjusted as described, to receive the fuelbundle, the bundle is pushed laterally into the magazine through theopen throat section 49, FIGS. 1 and 4. This magazine is normally closedand sealed by top section 45 of FIGS. 2 and 4, and side section 46 ofFIG. 4. These sections may be raised and subsequently closed as a unitby bracket 43. Appropriate linkages and motor means are shown as support40, and one or more air actuated pistons and cylinders 39. When thebundle has been horizontally positioned in the magazine it is coveredand sealed through the action of air actuated cylinders 39 which may beremotely operated. When the magazine is in closed position, appropriatescaling is provided at contact edges 58 of FIGS. 1 and 4.

In operation, nuclear fuel bundle 17 is urged by pusher head 20 throughthe gag module 24 (when gags 27 and 30 have been moved away from thebundle), past moving shear blade 25, and over the conduit opening 35,FIGS. 1, 2, and 3. The distance beyond the shear blade to which thebundle is urged is determined by the size of the fuel end cap or fitting18 to be removed by the first cut, and thereafter by the length of thepieces required for the subsequent dissolution step. The movement ofpusher head 20 and, therefore, of the fuel bundle 17, is accomplishedand controlled by shear feed push rod 11, FIGS. 1, 2, 8 and 9, shownpartially advanced. The motor means for achieving this motion is shownas drive mechanism 14 which operates outside of concrete barrier 22 andsupplies motive power through the concrete wall by means of rotatingshaft 13 affixed to pinion 12 which engages rack 15 on shear feed pushrod 11, FIGS. 1 and 2. Depending on the direction of rotation of shaft13, push rod 11 may be moved in the direction away from the shearinghead to thus permit the lateral positioning of a new fuel bundle in theempty magazine; or it may urge fuel bundle 17 forward for action by theshear. The moving shear blade 25 and gags 27 and 30 are retracted, andthe fuel bundle is advanced to a point where it extends beyond theshearblade 25 by a predetermined amount. Gags 27 and 30 arethen urged bymeans of hydraulic pressure against the fuel bundle, which is supportedagainst a fixed backing, whereby the fuel bundle is greatly compacted atthe point adjacent to the shear blade, and the cross-sectionconsequently is considerably reduced. More specifically, in theembodiment illustrated in FIGS. 2, 3 and 5, gag block 30 is slideablyarranged to move vertically and in a direction perpendicular to thepositioned bundle. This motion is imparted as a result of the gag blockbeing attached to the piston and piston rod assembly 74 of hydraulicallyactivated cylinder 31. When gag block 30 moves toward'the nuclear fuelbundle, it compresses the bundle against stationary plate 60 beneath.This gag, however, is preferably somewhat wider than the fuel bundle,and assuming it does not strike a non-compressible end fitting or fuelspacer, it reaches the end of its downward stroke at a predeterminedfixed point, positioned to permit reduction of the vertical dimension ofthe bundle to about percent of its original value, FIGS. 3 and 5.

Horizontal gag 27 has a vertical dimension equal to about 80 percent ofthe vertical dimension of the fuel bundle to be acted upon; accordingly,when the vertical gag block 30 reaches the lower end of its stroke, itis essentially in contact with the narrower horizontal gag 27. When thegags are activated, therefore, the vertical gag 30 which is sufficientlywide to overhang the horizontal gag 27, even when the latter is fullyretracted, compresses the end of the fuel bundle downwardly until saidvertical gag contacts or essentially contacts the horizontal gag. Atthis point it therefore remains fixed and restrains the bundle as thehorizontal gag 27 slides beneath to further compress the end of thebundle against shear anvil 53, FIG. 3.

With this novel arrangement the section of the fuel bundle adjacent tothe shear blade may be compressed at will in two directions at rightangles to each other and the hydraulically actuated gags may becontrolled and operated remotely.

Since the tubes which comprise the fuel bundle are frequently ratherbrittle, there would be considerable breakage of these elements if theface of the gag which contacts the fuel bundle were parallel to thebundle before compression. In such a case, considerable distortion andnotching of the tubes would occur at the edge of the gag away from theshearing mechanism. It has been found, however, that if the contour ofthe face of the gag block which contacts the tubes is so shaped thatcompressed, with the lowest edge adjacent to the shear. Further, theedge of the gag block towards the shear and the edge away from the shearshould be rounded. Such a contour is approximated in FIG. 7. With such acontour the curve traced by those tubes in contact with the gag, back tothe point where no compression has taken place, depicts a uniformlygentle curve or slope. A second horizontal gag may be used to furtherdistribute the strain on the tubes when they are subjected tocompression by the gags.

If one or both of the hydraulic cylinders which actuate the gags must belimited in size because of space considerations, the effectiveness ofthe smaller cylinder or cylinders can be enhanced by the use of abooster cylinder as illustrated in FIG. 5. Whereas cylinder 33activating horizontal gag 27 is shown as considerably smaller thancylinder 31 which activates vertical gag 30, the use of booster cylinder32, FIGS. 3 and 5, increases the effective force exerted by cylinder 33which can then apply force comparable to that provided by cylinder 31.

It will be noted in examining FIG. 5 that the dimension of the two gagsworking at right angles to one another limits the area of thecross-section to which the bundle can be compressed.

lt is further noted that travel of vertical gag 30 is limited byinterference with horizontal gag 27. The vertical gag 30 is advanceddownward to compress the bundle vertically, then the horizontal gag 27compresses the bundle horizontally. The total movement of the outer rowsof tubes is thus limited, to reduce potential breakage due to gagging.This is the essence of the two gag system.

Since the compressed cross-section of a small bundle must beconsiderably less than that of a large bundle, different size gags willbe used for fuel bundles within a specified size range.

To minimize shutdown time, in the preferred embodiment of the presentinvention, both gags and their actuating cylinders are contained in aremovable module as detailed in FIGS. 5 and 6. This module has a liftingring 54 and therefore can be removed from the nuclear shear, andreplaced by another, having gags which are either smaller or larger asthe case may require, by remote control.

When the end of the bundle is compressed and held by gags 27 and 30 aspreviously explained, shear blade 25 attached to shear block 57, FIGS.1, 3, and 8, is urged forward by remotely controlled hydraulic cylinder26 which lies outside concrete barrier 22 and transmits its powerthrough the barrier by means of piston rod 62. This actionsimultaneously shears off the extended section of the compressed fuelbundle and cuts communication between the magazine and the dissolutionapparatus not shown.

To insure that the flow of air between the magazine and dissolutionapparatus is not interrupted by the shear blade, by-pass valve 72, FIGS.1 and 3, provides the necessary communication during the interval whenthe shear blade is fully extended, with the exception that it is alwaysessentially closed when the magazine is opened for the insertion of afuel bundle, or for any other reason. It is desirable, however, that theflow of air to the dissolution apparatus be essentially constant at alltimes during the operation, to prevent acid vapors reaching the shearfrom said dissolution apparatus, and to prevent an outflow of air fromthe fuel bundle shear or the hot cell into the atmosphere. For thisreason the by-pass valve is designed so that at its position of minimalflow, it permits essentially the same air flow to the dissolutionapparatus when the magazine is open for charging, as occurs as a resultof leakage into the magazine when it is closed.

The cut pieces of the fuel bundle including the end fittings dropthrough conduit 35 to the dissolution apparatus. In those instances whenthe rear portion of the gags contact the relatively incompressible endfittings or tube spacers during the shearing operation, considerablecompression of the multitube section still occurs because of the slopingcontour of the gag faces.

A variation in the arrangement of the gags is also illustrated in FIGS.8, 9 and 10, which arrangement improves the degree of compression thatis possible when a gag encounters an end fitting or tube spacer. Also,the cross-section of the compressed portion of the fuel bundle obtainedby employing this embodiment is oblong, rather than essentially square.The advantage of this compression pattern lies in the fact that somewhatless sustained pressure is required in shearing through the bundle.

With this arrangement, there are two adjacent hori zontal gags 67 and68, FIG. 8. These adjacent gags may be independently actuated byparallel hydraulic cylinders contained within a removable module or bycylinders in tandem, as shown in FIG. 8. In this illustration, shaft 65attached to gag 68 is shown as surrounding shaft 66 attached to gag 67,said shaft being slideably and concentrically positioned within. Bothshafts extended, become the piston rods for piston-cylinder assemblies69 and 73 respectively. In our illustration,

both hydraulic cylinders, though in tandem, act independently, thepiston in cylinder 69 being essentially a concentric ring aboutindependently moving piston rod 66. This drawing is illustrative of justone of several ways in which such adjacent parallel acting gags may beactuated. These gags apply pressure on one side of the fuel bundle inthe same direction as the adjacent shear, and compress the bundleagainst anvil 53. To prevent the upward mushrooming of the tubes, anadjustable vertical restraining member 70 is lowered until it is closeto, or in contact with, the fuel bundle, before pressure is applied bythe horizontal gags 67 and 68. This vertical restraint essentiallymaintains the vertical dimension of the fuel bundle while the gagsconsiderably reduce its horizontal dimension usually to approximately 60to 70 percent of its original value.

This arrangement is of particular benefit in shearing off the endfittings, for when the forward gag 68 holds the front fitting,independently acting gag 67 is free to compress the tubes adjacent tothe fitting. Correspondingly, when rear gag 67 is holding the endfitting, gag 68 is free to compress the adjacent tubes. After the lastshear, the end fitting is pushed into open conduit 35 by push rod 11,thereby following the sheared pieces into the dissolution apparatus.

Finally, 38 in FIG. 1 represents an operationcontrolling console outsidethe concrete barrier, from which vantage point the entire operation issafely carried out. The fuel bundles are loaded into the magazine,aligned therein and the magazine closed and sealed. The bundle is urgedthrough the shear in increments, the front end fitting sheared off, andthe entire bundle is sheared into pieces suitable for dissolution. Bothfittings and the sheared pieces drop through open conduit 35 to thedissolution apparatus where the acid soluble nuclear fuel is leachedaway from the insoluble tubes, fittings, and tube separators with asuitable acid solution. Different size bundles can be accommodated, andwhen necessary, various sized gags can be substituted as part of acompact portable module, all by remote control.

It can thus be seen that the nuclear fuel bundle shear method of thepresent invention is manifestly capable of achieving the objects setforth in the specification, and while preferred embodiments of thepresent invention have been disclosed, it will readily be appreciatedthat the present invention is not limited thereto but may be otherwiseembodied within the scope of the following claims.

We claim:

1. The method of shearing spent nuclear fuel bundles having fittings ateach end, into pieces for treatment in a subsequent dissolution zone,which comprises the steps of:

a. charging the fuel bundle into a zone for shearing spent nuclear fuelbundles with a shear blade;

b. urging the bundle forward past the shear blade;

c. reducing the cross-section of the fuel bundle at a point adjacent tothe shear blade by first applying compressive forces to the bundle intwo directions substantially at right angles to each other, andsubsequently continuing the compressive force in one of those directionswhile restraining the bundle in the other;

d. shearing off the front end fittings;

e. continuously advancing the bundle past the shear blade whilecompressing and shearing the bundle into predetermined lengths; and

f. recovering the sheared lengths and both end fittings for treatment inthe subsequent dissolution zone.

2. The method of claim 1 wherein the subsequent dissolution zone is heldunder reduced pressure to create a flow of air from the zone forshearing the spent nuclear fuel bundles to the dissolution zone, andsaid flow of air is maintained at an essentially constant value duringboth the charging and the shearing operations.

3. The method of claim 2 wherein the end fittings and cut pieces of asheared spent nuclear fuel bundle are dropped through a conduit to thedissolution zone.

4. The method of shearing spent nuclear fuel bundles having fittings ateach end, into pieces for treatment in a subsequent dissolution zone,which comprises the steps of:

a. charging the fuel bundle into a zone for shearing spent nuclear fuelbundles with a shear blade;

b. urging the bundle forward past the shear blade;

c. reducing the cross-section of the fuel bundle at a point adjacent tothe shear blade by applying compressive force to the fuel bundle in onedirection while restraining the bundle in a direction substantiallyperpendicular to the direction of the applied compressive force.

d. shearing off the front end fittings;

e. continuously advancing the bundle past the shear bundle whilecompressing and shearing the bundle into predetermined lengths; and

f. recovering the sheared lengths and both end fittings for treatment inthe subsequent dissolution Zone.

5. The method of claim 4 wherein the subsequent dissolution zone is heldunder reduced pressure to create a flow of air from the zone forshearing the spent nuclear fuel bundles to the dissolution zone, andsaid flow of air is maintained at an essentially constant value duringboth the charging and the shearing operations.

6. The method of claim 4 wherein the end fittings and cut pieces of asheared spent nuclear fuel bundle are dropped through a conduit to thedissolution zone.

1. The method of shearing spent nuclear fuel bundles having fittings ateach end, into pieces for treatment in a subsequent dissolution zone,which comprises the steps of: a. charging the fuel bundle into a zonefor shearing spent nuclear fuel bundles with a shear blade; b. urgingthe bundle forward past the shear blade; c. reducing the cross-sectionof the fuel bundle at a point adjacent to the shear blade by firstapplying compressive forces to the bundle in two directionssubstantially at right angles to each other, and subsequently continuingthe compressive force in one of those directions while restraining thebundle in the other; d. shearing off the front end fittings; e.continuously advancing the bundle past the shear blade while compressingand shearing the bundle into predetermined lengths; and f. recoveringthe sheared lengths and both end fittings for treatment in thesubsequent dissolution zone.
 2. The method of claim 1 wherein thesubsequent dissolution zone is held under reduced pressure to create aflow of air from the zone for shearing the spent nuclear fuel bundles tothe dissolution zone, and said flow of air is maintained at anessentially constant value during both the charging and the shearingoperations.
 3. The method of claim 2 wherein the end fittings and cutpieces of a sheared spent nuclear fuel bundle are dropped through aconduit to the dissolution zone.
 4. The method of shearing spent nuclearfuel bundles having fittings at each end, into pieces for treatment in asubsequent dissolution zone, which comprises the steps of: a. chargingthe fuel bundle into a zone for shearing spent nuclear fuel bundles witha shear blade; b. urging the bundle forward past the shear blade; c.reducing the cross-section of the fuel bundle at a point adjacent to theshear blade by applying compressive force to the fuel bundle in onedirection while restraining the bundle in a direction substantiallyperpendicular to the direction of the applied compressive force. d.shearing off the front end fittings; e. continuously advancing thebundle past the shEar bundle while compressing and shearing the bundleinto predetermined lengths; and f. recovering the sheared lengths andboth end fittings for treatment in the subsequent dissolution zone. 5.The method of claim 4 wherein the subsequent dissolution zone is heldunder reduced pressure to create a flow of air from the zone forshearing the spent nuclear fuel bundles to the dissolution zone, andsaid flow of air is maintained at an essentially constant value duringboth the charging and the shearing operations.
 6. The method of claim 4wherein the end fittings and cut pieces of a sheared spent nuclear fuelbundle are dropped through a conduit to the dissolution zone.